veproza

Getting u-blox MAX-7C GPS to work with Assisted A-GPS

So you got your u-blox GPS and wired it up only to look at it struggling to get a valid fix? Under less than ideal conditions, it can take a better part of half an hour. That's because unlike your smartphone GPS, it doesn't have the luxury of having downloaded all the auxiliary navigation data (almanacs and the lot) out-of-band, via fast mobile connection. Instead it relies on the satellite's signal itself, which is being transmitted to you at meager 50 bits per second (I'm not missing "kilo" there, it's three orders of magnitude slower than your 2G GPRS connection).

Luckily, the u-blox receivers are fitted with what the company calls "AssistNow" capability and it does exactly the same thing your iPhone does - feeds the GPS with pre-downloaded almanacs, speeding up the acquisition process to mere seconds.

In principle, the process looks easy enough - we just need to download the data, and then push them to the receiver. Sadly, the AssistNow documentat

kellertk

The PiSugar2 is a battery board for the Raspberry Pi Zero. It has an integrated RTC chip available over I2C, but there are no drivers included in the kernel with the latest release of the pwnagotchi (or Kali in general). It's a ZXW Shenzhen SD3078; there is surprisingly little information out there about this chip. I suspect it's newish.

The PiSugar folks expect you to install Pisugar Power Manager, which is a web service to get battery status and set the RTC. I prefer to use the standard hwclock utility, because I don't need the extra function in the web interface. There is driver support for this chip in kernels 5.1 or newer, so we can grab that and compile it as an out of tree module. You may be able to adapt these ins